Dynamic impact of intelligence on verbal-humor processing: Evidence from ERPs and EROs

Intelligence (measured by IQ) varies across individuals. An individual's IQ has been evidenced to be positively associated with verbal-humor production. However, to our knowledge, no study to date has examined how intelligence affects verbal-humor processing. The objective of this current electroencephalogram (EEG) study is to explore the dynamic impact of intelligence on processing patterns in three stages of verbal-humor processing from both temporal and oscillatory perspectives. Twenty-six subjects were recruited and required to read setup-punchline type statements in three conditions (funny, unfunny and unrelated). Event-related Potentials (ERPs) analysis found the earliest differences between relatively higher IQ (RHI) group and relatively lower IQ (RLI) group in dealing with unfunny conditions in the P200 component due to its role as a neural marker mediated by intelligence in language processing; more importantly, the processing patterns in two stages, incongruity detection and mirth, were found to be modulated by intelligence levels: the analysis of the N400 effect presented typical characteristics of incongruity detection for RHI group, while nontypical characteristics close to N300-like effect were found for RLI group; in the stage of mirth, RHI group presented a sustained P600 effect, while RLI group presented proper features of emotion processing. At the global level, these results indicate that people with different intelligence levels may employ dual-pattern model in processing two stages among three stages of verbal-humor appreciation. Event-related Oscillations (EROs) analysis revealed the functional role of the theta band and disclosed the impact of intelligence levels on the early stage of verbal-humor processing from the perspective of ERO. In the future research, further methodological considerations should be included to clarify the innate brain mechanisms aiming at examining intelligence differences regarding verbal-humor processing or indeed on any other issues.